UBC Global Inventory Reveals Bottom Trawling Impacts Thousands of Fish Species, Including Critically Endangered Groups

The first global inventory of bottom trawl catches reveals one in seven species are threatened with extinction, including the critically endangered giant guitarfish.

By: AXL Media

Published: Apr 8, 2026, 11:43 AM EDT

Source: Information for this report was sourced from EurekAlert!

The Clearest Picture of Seafloor Destruction

Bottom trawling—a practice where heavy nets are dragged across the ocean floor—has long been criticized for its environmental impact, but its true breadth has remained largely unquantified. Researchers at the University of British Columbia (UBC) have now published the world’s first global inventory in Reviews in Fish Biology and Fisheries, drawing on over 9,000 records spanning from 1895 to 2021. Dr. Sarah Foster, the study's lead author, emphasizes that the findings reveal a scale of biodiversity loss previously hidden from public and scientific view. By sweeping up everything in their path, these trawlers are effectively destabilizing the marine systems that commercial fisheries rely on.

Extinction Risks Hidden in the Net

The data reveals a stark conservation crisis: among the fish species caught with an assigned IUCN Red List status, one in seven is threatened or near-threatened with extinction. The inventory includes sightings of the critically endangered giant guitarfish, the endangered zebra shark, and multiple vulnerable seahorse species. Furthermore, one-quarter of the reported species are classified as "data deficient" or have never been evaluated. This means a significant portion of global bottom trawling is operating without any understanding of its impact on evolutionarily unique or rare marine life.

Impact on the Marine "Tree of Life"

According to the study, bottom trawling does not discriminate between common food fish and rare, distinct groups. Entire branches of the marine tree of life are being removed, including commercially critical families like jacks and croakers, as well as rare groups such as the plough-nosed chimera. Co-author Syd Ascione notes that this lack of selectivity puts immense pressure on species that scientists still know very little about. By capturing all or most species within certain families, the practice risks permanently altering the biodiversity of the seafloor.